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US008289378B2 (12) United States Patent Soto-Thompson et a]. (54) (75) HIGH RESOLUTION DIGITAL VIDEO COLPOSCOPE WITH BUILT-IN POLARIZED LED ILLUMINATION AND COMPUTERIZED CLINICAL DATA MANAGEMENT SYSTEM Inventors: Marcelo Esteban Soto-Thompson, Honolulu, HI (US); Andrew Beaumont Oct. 16, 2012 OTHER PUBLICATIONS D. G. Ferris, et al., “Modern ColposcopyiTextbook and Atlas,” pp. 250-662, American Society for Colposcopy and Cervical Pathology Kendall/ Hunt Publishing Co., Dubuque, Iowa. B.S. Apgar et al., “Colposcopy: Principles and Practice,” pp. 115 132, W.B. Saunders Company, Philadelphia, PA 2002. Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 947 days. multispectral digital colposcope,” Gynecologic Oncology 107, S21 Gustafsson, Honolulu, HI (US) (73) Assignee: STI Medical Systems, LLC, La Jolla, CA (US) Notice: US 8,289,378 B2 K. T. Schomacker et al., Novel optical detection system for in vivo identi?cation and localization of cervical intra-epithelial neoplasia, J. Biomed Optics 11(3), pp. 034009-1 to 034009-02, 2006. J .E. Kendrick et al., “LUMATM Cervical Imaging System,” Expert Rev. Med. Devices 4(2), pp. 121-129, 2007. E. Hecht., “Optics,” pp. 270-332, Addison-Wesley, 2nd edition 1987. Welch Allyn, “Video Colposcope,” Directions for Use, 2007. S. Nakappan et al., “Methodology of real time quality control for the Whitesell, Honolulu, HI (US); Ulf Peter (*) (10) Patent N0.: (45) Date of Patent: S222, 2008. (21) Appl. N0.: 12/291,s90 (22) Filed: Acgih, “Electromagnetic Radiation and Fields,” pp. 13-43, 2007, Cincinati, OH. Nov. 14, 2008 * cited by examiner (65) Prior Publication Data US 2010/0026785 A1 Feb. 4, 2010 Related US. Application Data (60) Provisional application No. 61/137,684, ?led on Aug. 1, 2008. (51) Int. Cl. Primary Examiner * Tonia L Dollinger Assistant Examiner * Adam Cooney (74) Attorney, Agent, or Firm * Martin E. Hsia (57) H04N132/02 (52) (58) This invention uses LEDs and cross-polarization to produce (2006.01) US. Cl. ............................. .. 348/47; 348/57; 348/58 Field of Classi?cation Search ................... .. 348/47 See application ?le for complete search history. (56) ABSTRACT References Cited bright, high-resolution digital images, both With and Without glint (Which adversely affects the clarity of standard colpo scopic images), as Well as streaming video at loWer resolu tion. The invention alloWs for deeper layers of the tissue to be more e?iciently visualized at multiple magni?cations, thereby enhancing the invention’s diagnostic capabilities, U.S. PATENT DOCUMENTS 5,929,443 A 6,766,184 B2 2006/0184040 A1* 2006/0215406 A1* 7/1999 Alfano et al. and it includes a focusing subsystem and a computerized data management system to archive and annotate still image data. 7/ 2004 Utzinger et al. 8/2006 Keller et al. 9/2006 Thrailkill .................... .. 362/252 ................ .. 600/476 9 Claims, 9 Drawing Sheets US. Patent 0a. 16, 2012 Sheet 1 019 FIG. 1 US 8,289,378 B2 US. Patent 0a. 16, 2012 Sheet 2 of9 US 8,289,378 B2 34 49 36 FIG. 2A 34 49 36 FIG. 2B 34 49 36 FIG. 2C US. Patent 0a. 16, 2012 Sheet 3 of9 US 8,289,378 B2 FIG. 3A 34 > 49 36 FIG. 3B 34 49 36 FIG. 3C US. Patent 0a. 16, 2012 US 8,289,378 B2 Sheet 4 0f 9 49 FIG. 4A LA 4 49 FIG. 4B 4 49 36 FIG. 4C US. Patent 0a. 16, 2012 Sheet 5 of9 FIG. 5A FIG. 5B US 8,289,378 B2 US. Patent Oct. 16, 2012 Sheet 6 0f 9 US 8,289,378 B2 86 85 83 FIG. 6A 84 FIG. 6B US. Patent 0a. 16, 2012 Sheet 7 of9 US 8,289,378 B2 2O 4/’ 34 I‘ 24 4/’ FIG. 7A 34 22 FIG. 7B US. Patent 0a. 16, 2012 Sheet 8 of9 US 8,289,378 B2 20, 24 FIG. 8A 20, 24 IG. 8B IG. 8C US. Patent 0a. 16, 2012 Sheet 9 of9 3 6 US 8,289,378 B2 ‘_-"-’ 10 ¢—-——! 11 ¢——> 12 <———& 13 I """ ". *"--": FIG. 9 14 | US 8,289,378 B2 1 2 HIGH RESOLUTION DIGITAL VIDEO COLPOSCOPE WITH BUILT-IN POLARIZED LED ILLUMINATION AND COMPUTERIZED CLINICAL DATA MANAGEMENT SYSTEM addition, different colored ?lters are often used to accentuate blood vessel patterns that cannot be easily seen by using regular White light. Although the standard colposcopic exam and regular screening have led to dramatic decreases in the overall inci dence of cervical cancer, neW technologies can further This application claims priority to US. provisional patent application No. 61/137,684 for “CervicalMD C30 Imaging Subsystem”, ?led on Aug. 1, 2008. enhance the sensitivity and speci?city of currently accepted colposcopic practices. Digital imaging is one such technol ogy that can revolutioniZe medical imaging and enables sophisticated computer programs to assist the physician With CAD (Computer-Aided-Detection or Computer-Aided-Di agnosis). The combination of digital imaging and CAD could have a direct impact on improving Women’s health, and TECHNICAL FIELD This invention relates to medical imaging and, more spe ci?cally, to a device and process that suppresses specular decrease the associated cost, by automatically identifying CIN in real-time With high sensitivity and speci?city. This re?ection (glint) through cross-polarization, producing bright cross-polarized and parallel-polarized images at multiple magni?cations in real-time, thereby enhancing the visualiZa Would mean feWer false-positive biopsies, or ultimately, elimination of biopsies. A CAD system operating as an tion of diagnostically relevant features Within a subject (such adjunct to colposcopy could minimize the high variability among colposcopists and enable consistent, higher standards as organs or tissue). The device also preferably includes a focusing subsystem, and a computeriZed data management 20 system for archival purposes and for the annotation of digital data. for accuracy. A product realiZation Where a CAD system is incorporated into a loW-cost device, creating in effect a machine expert colposcopist, Would have the potential of increasing the availability and cost-effectiveness of screening in developing countries. BACKGROUND ART 25 Although this invention is being disclosed in connection Digital imaging provides a means for implementing a com puteriZed clinical data management system. This data man With cervical cancer, it is applicable to many other areas of agement system could provide management, display, and medicine. Uterine cervical cancer is the second most common cancer in Women WorldWide, With nearly 500,000 neW cases annotations of the acquired digital data, as Well as automation of the Work?oW associated With colposcopy. The system and over 270,000 deaths annually (IARC, “Globocan 2002 database,” International agency for research in cancer, 2002, 30 alloW the use of electronic patient data records, and interface and integrate With standard systems for handling, storing, printing and transmitting information in medical imaging, incorporated herein by reference). Because invasive disease is preceded by pre-malignant Cervical Intraepithelial Neopla sia (CIN), if detected early and treated adequately, cervical cancer can be universally prevented (D. G. Ferris, J. T. Cox, D. M. O’Connor, V. C. Wright, and J. Foerster, Modern Col could simplify the administration of patient data and history, such as DICOM (Digital Imaging and Communication in 35 Medicine). DICOM is a standard for handling, storing, print ing, and transmitting information in medical imaging. It poscopy. TexlbookandAllas, pp. 1-699,American Society for includes a ?le format de?nition and a network communica Colposcopy and Cervical Pathology, 2004, incorporated herein by reference). Colposcopy is the primary diagnostic tions protocol. The communication protocol is an application protocol that uses TCP/IP (the standard intemet protocol) to method in the United States to detect CIN and cancer folloW ing an abnormal cytological screen (Papanicolaou smear or 40 communicate betWeen systems. DICOM ?les can be exchanged betWeen tWo entities that are capable of receiving pap smear). The purpose of a colposcopic examination is to image and patient data in DICOM format. Digital imaging identify and rank the severity of lesions, so that biopsies representing the highest-grade abnormality can be taken, if necessary. The biopsies are then microscopically evaluated alone is also a pre-requisite for telemedicine applications, further increasing the availability of screening and detection 45 For the colposcopic exam, an optical colposcope is typi cally used, and has been used for such purposes for almost 80 years. A colposcope is a binocular microscope With a built in White light source and objective lens attached to a support ery upon Which a CAD system operates must be of high visual quality. One factor contributing to poor cervical imagery is specular re?ection (glint), Which is perfect, mirror-like 50 mechanism (B. S. Apgar, BrotZman, G. L. and SpitZer, M., Colposcopy: Principles and Practice, W.B. Saunders Com pany: Philadelphia, 2002, incorporated herein by reference). At loW levels of magni?cation, (comparable to a circular ?eld of vieW of approximately 50 to 100 mm) the entire vagina and cervix can be visualiZed and this setting is typically used to obtain a general impression of the surface structure and archi tecture. Medium magni?cations (comparable to a circular 55 60 mirror itself. Because this color information may be impor tant in detecting cancer precursors, reducing the amount of glint in an image is helpful in producing high-quality images vagina and the cervix. These higher magni?cations are often necessary to detect and identify certain vascular patterns for diagnostic purposes. HoWever, it is not alWays desirable to eliminate all the glint from an image because an image of a tissue or organ that contains glint may look more natural and indicative of the presence of more advanced pre-cancerous or cancerous lesions. During the colposcopic exam, acetic acid and iodine solutions are usually applied to the surface of the cervix to improve the visualiZation of abnormal areas. In re?ection of light from a surface, in Which light from a single incoming direction (i.e., a ray) is re?ected into a single out going direction. Glint is undesirable because it effectively eliminates color information in an image, and also results in the introduction of artifacts (misrepresentations of tissue structures) in the image. Glint eliminates color information because its mirror-like re?ection shoWs the color of the light source, and not of the underlying tissue, much as a mirror shoWs the color of a re?ected light, and not the color of the ?eld of vieW of approximately 15-30 mm) and high magni? cations (comparable to a circular ?eld of vieW of approxi mately 5-15 mm) are utiliZed for detailed analysis of the in rural areas and developing countries. In order to reliably assess colposcopic features, the imag by a pathologist based on the morphology of the tissue. 65 three-dimensional. In addition, colposcopists analyZe the glint patterns on the cervix to assess the surface contour of lesions, an important feature used to evaluate lesion severity. US 8,289,378 B2 4 3 as vascular patterns, bright light sources are helpful in pre The prior art describes a number of Ways to reduce the serving the clarity of an image. in?uence of or eliminate glint. Physicians using optical col HoWever, these bright light sources must not exceed poscopes can change their ?eld-of-vieW and/or the lightning conditions to either move the glint to different parts of the cervix and maintain the region of interest glint-free, or to a acceptable thresholds for patient exposure to ultraviolet (UV) and infrared (IR) radiation (as described by the American Conference on Governmental Industrial Hygienists (ACGIH) in, Threshold Limit Values (TLVs) for Chemical Substances large extent eliminate the glint completely. Another method involves using multiple light sources directed at different angles toWards an object (see for example K. T. Schomacker, T. M. Meese, C. Jiang, C. C. Abele, K. Dickson, S. T. Sum, and R. F. FleWelling, Novel optical detection system for in vivo identi?cation and localization of cervical intra-epithelial neoplasia, J. Biomed Optics 11(3), 034009-1-12, 2006, and J. and Physical Agents and Biological Exposure Indices (BEIs), Signature Publications, 2008, incorporated herein by refer ence). Exposure to UV radiation has the potential of acute adverse health effects such as erythema and photokeratitis, and can cause DNA damage in the cells. Presently, the expo sure to UV radiation is minimized, if not completely elimi nated, by employing a UV blocking ?lter in the light source E. Kendrick, W. K. Huh, and R. D. Alvarez, LUMATM Cer vical Imaging System, Expert Rev. Med. Devices 4(2), 121 beam path prior to the light being available to human vieWing 129, 2007, incorporated herein by reference). By illuminating and exposure (such as described in Welch Allyn Video Col the cervix at different angles and acquiring several images, the position of the glint on the surface of the cervix is different betWeen the different images, and the images can be com bined to create a glint-free combined image. The use of polarization ?lters, each of Which functions in the same Way as a pair of polarized sunglasses, is another glint 20 ogy 107, S21-S222, 2008, incorporated herein by reference). reducing or eliminating technique Well knoWn in the art (see for example, E. Hecht., Optics, Addison-Wesley, 1st edition 1972, 2nd edition 1987, 3rd edition 1997, 4th edition 2001). 25 The polarization ?lter method utilizes one polarization ?lter placed at the light source and another ?lter rotated to approxi blocking ?lter, the heat generated by the IR radiation puts this cross polarization scheme, the re?ections from the sur glint-free object or image. Cross-polarization is employed, for example, in commercially available colposcopes (Welch Allyn Video Colposcope, User’s manual, 2007, incorporated herein by reference), and research colposcope systems (such Many bright light sources also contain a large amount of IR Which is essentially excess heat. Similar to UV radiation, the exposure to IR radiation is minimized or eliminated by the utilization of an IR blocking ?lter. Although the heat exposure of the user or patient is minimized or eliminated by an IR mately 900 positioned in front of the detector. By applying face of the object under study are substantially minimized, if not completely eliminated, and the end result is an essentially poscope, User’s manual, 2007, incorporated herein by refer ence) and S. Nakappan, S-Y. Park, D. Serachitopol, R. Price, M. Cardeno, S. Au, N. Mackinnin, C. MacAulay, M. Follen, and B. M. Pikkula, Methodology of real time quality control for the multispectral digital colposcope, Gynecologic Oncol 30 stress on the optical and mechanical components of the light source assembly and may signi?cantly decrease the lifetime of the components, as Well as of the light source itself. Further, some bright light sources require a long start-up time before the output intensity is stable. This means there is a Wait time before the device can be utilized in a clinical 35 examination, possibly decreasing the cost-effectiveness of as described in S. Nakappan, S-Y. Park, D. Serachitopol, R. such a device. Price, M. Cardeno, S. Au, N. Mackinnin, C. MacAulay, M. Follen, and B. M. Pikkula, Methodology of real time quality A third factor contributing to poor cervical imagery is non-uniform lighting, Which can lead to non-uniformity of control for the multispectral digital colposcope, Gynecologic Oncology 107, S21-S222, 2008, incorporated herein by ref 40 diagnosis based on the resulting image. erence). In these systems, the polarization ?lters are typically actuated by computer controlled rotating ?lter Wheels or manually operated rotating ?lter holders, either on the light source side or detection side, or both. Being able to remove or rotate the polarization ?lters, alloWs for the acquisition of 45 both cross-polarized imagery Without glint and regular imag ery With glint. A drawback of using manually operated or computer controlled mechanical assemblies to sWitch or rotate the polarization ?lters is the inevitable Wear and tear and ultimate failure of these units over time. In addition, mechanical sWitch or rotational devices Will introduce a delay 50 betWeen the image vieWing or capture of cross polarized and regular imagery. During this delay, signi?cant movement of the colposcope and/ or the patient can occur. This movement can make it extremely dif?cult to register (align) images and track diagnostically important features, such as blood vessels of varying sizes. This is especially true for a fully automated 55 body surface Which includes recording at a ?rst time a ?rst multispectral digital image of the surface including the spectral digital image of the surface including the region, and 60 comparing the ?rst and the subsequent images. Also, such a method in Which the ?rst and subsequent images are high magni?cation images, and further including recording loW magni?cation images that include the high magni?cation respect to imaging systems incorporating polarizing compo nents, is that polarization inherently results in a loss of light. Because brightness (or intensity) is an integral part of the achievable contrast (i.e. the difference in visual properties that make an object distinguishable from other objects and the background) in the captured images, and because the contrast of an image is important in detecting cancer precursors such The folloWing patents may be considered relevant to the ?eld of the present invention: US. Pat. No. 4,979,498 to Oneda et al., incorporated herein by reference, discloses a video cervicoscope system for the examination of the cervix comprising: a rigid, elongated tubular member having a light guide; imaging means at the distal end of said tubular member, a disposable, light-trans mitting, sleeve disposed about the distal end of said tubular member; and transmitting means to transmit an image vieWed by said imaging means proximally to a control box Wherein said image is received and stored. US. Pat. No. 5,836,872 to Kenet et al., incorporated herein by reference, discloses a method for monitoring a region of a region, recording at a subsequent time a subsequent multi CAD system that does not rely on human direction or inter vention. Another factor contributing to poor cervical imagery, With the brightness (or intensity) in the resulting image. Non uniforrnity of brightness impairs the potential accuracy of any images. Also disclosed is a method for forming a diagnosti cally useful classi?cation of pigmented skin lesions, using 65 such a method to construct a database containing quantita tively extracted selected features from images recorded from a plurality of skin lesions, and correlating the features from US 8,289,378 B2 5 6 each such lesion in the database With the medical history of the skin lesion from Which the image Was recorded. Further, a method for diagnosis of a premelanomatous or early mela nomatous condition includes using the method for character a desired object. Re?ected light from the object entering the housing through the glass cover is passed through a second polarizer, Which is adjustably mounted in the barrel portion of the housing and Which is preferably oriented to pass depolar izing a surface region including the lesion and comparing the ized light emitted from an illuminated object, and is then imaged by optics onto a black and White CCD (charged features of the lesion so obtained With the features in a data base obtained from a number of skin lesions including lesions knoWn to be premelanomatous or early melanomatous, or coupled device) detector (camera). The optics may include a lens that is disposed Within the barrel portion and is adjustably spaced relative to the CCD detector. The detector is coupled classifying the features of the lesion according to the diag nostically useful classi?cation of pigmented skin lesions. U.S. Pat. No. 5,929,443 to Alfano et al., incorporated herein by reference, discloses a method and apparatus for the imaging of objects based on the polarization and depolariza to a Wireless transmitter mounted in the housing, the trans mitter transmitting the output from the detector to a remotely located Wireless receiver. The Wireless receiver is coupled to a computer, Which then processes the output from the detec tor. The processed output is then displayed on a display. The tion of light. In one embodiment, a surface of a turbid medium is imaged by illuminating the surface of the turbid medium With light, Whereby light is backscattered from the illumi nated surface of the turbid medium, detecting a pair of complementary polarization components of the backscat tered light, and forming an image of the illuminated surface using the pair of complementary polarization components. The illuminating light is preferably polarized (e.g., linearly display may be remotely situated for remote expert diagnosis. U.S. Pat. No. 6,766,184 to Utzinger et al., incorporated herein by reference, discloses methods and apparatus for generating multispectral images of tissue. The multispectral images may be used as a diagnostic tool for conditions such as 20 polarized, circularly polarized, elliptically polarized), Where, for example, the illuminating light is linearly polarized, the pair of complementary polarization components are prefer ably the parallel and perpendicular components to the polar ized illuminating light, and the image is formed by subtract ing the perpendicular component from the parallel cervical cancer detection and diagnosis. Primary radiation is produced With an illumination source. The primary radiation is ?ltered to select a ?rst Wavelength and a ?rst polarization. Tissue is illuminated With the ?ltered primary radiation to generate secondary radiation, Which is ?ltered to select a 25 second Wavelength and a second polarization. The ?ltered secondary radiation is collected With a detector, and a plural ity of multispectral images of the tissue is generated accord component, by taking a ratio of the parallel and perpendicular ing to different combinations of ?rst and second Wavelengths and ?rst and second polarizations With an analysis unit in components or by using some combination of a ratio and operable relation With the detector. Apparatus utilizing the invention include endoscopes and colposcopes. difference of the parallel and perpendicular components. U.S. Pat. No. 5,989,184 to Blair, incorporated herein by reference, discloses an apparatus for digital colposcopy and videography Which comprises a digital imaging camera that is operably coupled to the optical path of the digital colpo 30 scope by means of a beam splitter so that a digital image of the 35 U.S. Patent Application Publication No. 2006/ 0141633 to Balas, incorporated herein by reference, discloses a method and an apparatus for the in vivo, non-invasive, early detection of alterations and mapping of the grade of these alterations, caused by the biochemical and/or the functional characteris tics of epithelial tissues during the development of tissue atypias, dysplasias, neoplasias and cancers. The method is 40 poral and spectral alterations in the characteristics of the light cervico-vaginal tissue can be captured. The digital imaging camera and digital colposcope are mounted to one end of an articulating arm of the apparatus. Digital processing means is operably connected to the digital imaging camera to create a digital image. The digital processing means is housed in a stand of the assembly. U.S. Pat. No. 6,277,067 to Blair, incorporated herein by reference, discloses a method and portable apparatus for the based on the simultaneous measurement of the spatial, tem that is re-emitted from the tissue under examination, as a result of a combined tissue excitation With light and special chemical agents. The topical or systematic administration of visual examination and grading of cervical epithelium by means of a hand-held colposcopy assembly capable of pro 45 these agents results in an evanescent contrast enhancement betWeen normal and abnormal areas of tissue. The apparatus ducing a digital image of the cervix. The apparatus enables real-time imaging and archiving of images of the entire cervix enables the capturing of temporally successive imaging in for the purpose of detecting cancerous and pre-cancerous measured data, the characteristic curves that express the agent-tissue interaction kinetics, as Well as numerical param eters derived from these data, are determined in any spatial tissue, and by virtue of computerized image processing, sug gests an objective diagnosis of the cervical epithelium by one or more spectral bands simultaneously. Based on the 50 point of the examined area. Mapping and characterization of means of a loW cost, portable, hand-held digital colposcope. U.S. Pat. No. 6,587,711 to Alfano et al., incorporated herein by reference, discloses an apparatus for examining an object, such as skin, mucosa and cervical tissues, for the the lesion are based on these parameters. U.S. Patent Publication No. 2006/ 0184043 to Tromberg et al., incorporated herein by reference, discloses an improve 55 ment in a method for quantitative modulated imaging to per form depth sectioned re?ectance or transmission imaging in a turbid medium, such as human or animal tissue. The method is directed to the steps of encoding a periodic pattern of illumination, preferably With a ?uorescent excitation Wave 60 portion of the housing. A manually-operable sWitch for con length When exposing a turbid medium to the periodic pat tern, to provide depth-resolved discrimination of structures Within the turbid medium; and reconstructing a non-contact trolling actuation of each of the four LED’s is accessible on three dimensional image of the structure Within a turbid purpose of detecting cancer and precancerous conditions. In one embodiment, the apparatus includes a gun-shaped hous ing having a handle portion and a barrel portion. The front end of the barrel portion is open, and a glass cover is mounted therein. Red, green, blue, and White LED’s are disposed Within the handle portion of the housing, and are electrically connected to a battery and are also disposed Within the handle the handle portion of the housing. An optical ?ber is disposed inside the housing and is used to transmit light from the four LED’s through a ?rst polarizer disposed in the barrel portion of the housing and then through the glass cover to illuminate medium. As a result, Wide ?eld imaging, separation of the 65 average background optical properties from the heterogene ity components for a single image, separation of super?cial features from deep features based on selection of spatial US 8,289,378 B2 8 7 frequency of illumination, or qualitative and quantitative structure, function and composition information, is extracted from spatially encoded data. The present invention is a device that preferably creates pairs of clear images, a glint-free image (cross-polarized image) and an image With glint (parallel-polarized image), at multiple magni?cations. The term cross-polarized (XP) US. Patent Application No. 2006/0215406 to Thrailkill, refers to When a ?rst polarization orientation is perpendicular to a second polarization orientation, Whereas the term paral lel-polarized (PP) refers to When a ?rst polarization orienta tion is parallel to a second polarization orientation. In the present invention, PP can also mean singly-polarized, Where there is only one polarization orientation, or unpolarized. The XP and PP images can be used in conjunction With each other for diagnostic purposes. For example, XP and PP images can be registered (aligned) and then faded into each other to aid a clinician in cancer detection (as described in co-pending, incorporated herein by reference, discloses a medical diag nostic instrument, Which could be a colposcope for examin ing cervical tissue, and includes a light source comprising an annular array of high intensity light emitting diodes (LEDs). The LED array includes a central access opening Which pro vides vieWing access for the colposcope optical components to the illumination site. The array includes a plurality of sets of LEDs, With each set including a red, blue and green emit ting LED. The intensities of the red, blue and green LEDs, respectively, are controllable With a controller to continu commonly assigned US. patent application Ser. No. 12/228, ously vary or tune the spectral characteristics of the illumi nation from the light source. Selected color mixes can be stored in a memory for later retrieval. US. Patent Publication No. 2007/0213590 to Squicci 298, entitled “A Method of Image Manipulation to Fade BetWeen TWo Images” ?led Aug. 11, 2008, incorporated herein by reference). Fading betWeen the tWo images alloWs a clinician to detect important features that may be masked by narini, incorporated herein by reference, discloses a portable multi-functional endoscopic device and method for use in the 20 examination of tissue to permit diagnostic, therapeutic or glint, While at the same time retaining to a desired extent the natural and three-dimensional shape of tissue or an organ (such as the cervix) in the image. To suppress glint, the ?rst preferred embodiment prefer anatomical assessment data to be transmitted, recorded, or analyzed. The device includes a base unit sized and con?g ably employs cross-polarization, Which alloWs for deeper ured to be held in a human hand to permit functional and directional control of the device, an interchangeable head assembly sized and con?gured to be inserted into an ori?ce being removably connectable to the base unit, and an in?at able tissue stabilizer disposed external to a distal end of the device. In preferred aspects, the endoscopic device has an 25 image sensor, light source, lens, air pump, and Working tools. 30 layers of tissue to be visualized at multiple magni?cations, thereby further enhancing the invention’ s diagnostic capabili ties. To produce a brighter and more uniform illuminated surface With a denser light emission than typical ?uorescent and incandescent light sources, the light source in this embodiment preferably includes tWo sets of multiple light emitting diodes (LEDs), Which are preferably turned on and US. Patent Application No. 2008/ 0049997 to Chin, incor porated herein by reference, discloses an image enhancement off rapidly by electronically changing the operating current or system that includes a data source Which provides image data voltage, to directly and uniformly illuminate a ?eld of vieW. The light from the LEDs is preferably polarized through an illumination polarizer before reaching the ?eld of vieW. of an object, enhancement data storage including image enhancement information, an image enhancement unit con 35 The present invention’s use of LEDs offers several ben e?ts. LEDs, unlike ?uorescent and incandescent lights, are solid-state components, alloWing for faster sWitching on and ?gured to enhance the image data based on the image enhancement information, and a color display con?gured to display a monochrome image representing the enhanced image data on a screen thereof. The enhanced image data may include a gray level scale of at least 32 bits per pixel. US. Patent Application Publication No. 2005/004365 to 40 off, so that sWitching betWeen parallel-polarized image acquisition and cross-polarized image acquisition can be achieved more easily and quickly. The invention preferably Zelenchuk, incorporated herein by reference, discloses a sys uses ?xed illumination polarizers (IP) in front of the tWo sets tem and method for the in situ discrimination of healthy and of LEDs, instead of mechanically moving polarizing ?lters. Rapidly sWitching betWeen the LEDs (rapidly alternating diseased tissue. A ?beroptic probe is employed to direct ultra violet illumination onto a tissue specimen and to collect the ?uorescent response radiation. The response radiation is observed at three selected Wavelengths, one of Which corre sponds to an isosbestic point. In one example, the isosbestic point occurs at about 431 nm. The intensities of the observed signals are normalized using the 431 nm intensity. A score is 45 50 determined using the ratios in a discriminant analysis. The tissue under examination is resected or not, based on the diagnosis of disease or health, according to the outcome of the discriminant analysis. 55 DISCLOSURE OF THE INVENTION The present invention addresses the problem of glint inher ent in performing a standard colposcopic exam and addresses the limitations of using mechanical ?lter Wheels or rotating ?lter assemblies, the brightness of the light source, the health aspects of exposure to UV and IR hazards, and the extended start-up time of most bright light sources by employing a 60 non-mechanical, non-moving (?xed or stationary) polariza tion assembly With an electronically sWitchable light source each set of LEDs on and off) also reduces the in?uence from patient movement betWeen successive images, alloWing for better registration (alignment) betWeen successive images and improving the possibility of detection of diagnostically important features. An LED assembly is also less expensive 65 and more compact than the typical illumination sources using either ?uorescent or incandescent lighting With bundles of ?ber optic cables, and LEDs are also more reliable than using either ?uorescent or incandescent lights because they are rated for approximately 50,000 hours of use and one million on/off cycles. As a comparison, the rated lifetimes for ?uo rescent or incandescent lights are typically less than 10,000 hours With many having a typical lifetime of only 1000 hours. LEDs also generate less heat than ?uorescent and incandes cent lights. Therefore, less cooling and less thermal insulation are required for the device housing, alloWing for smaller poWer suppliesie.g., smaller fans that produce less noise and vibration for patient and operator comfort. The thermal e?iciency of LEDs also reduces heat, Which generates ther mal expansion of the device’s mounts and can degrade the optical quality of the images. LEDs also require less poWer system based on high-intensity light emitting diodes (LEDs), and are more e?icient in converting electrical poWer con Which do not to generate any UV or IR radiation. sumption to visible light, ultimately reducing the poWer con US 8,289,378 B2 9 10 sumption of the device, and enabling battery operation in cervical tissue) in one direction (e.g., toWards one of the remote areas, if necessary. Further, light emitted by an LED is cameras), diffuse light refers to light that is scattered in all also emitted over a broad ?at area unlike conventional incan directions and is unpolarized. It is Well knoWn in the art that descent and ?uorescent lights, thus providing for more uni form illumination. unpolarized light can be described as a combination of both PP and XP light. Because a camera captures only that portion of the diffuse light that is re?ected in the camera’s direction, the diffuse re?ected light does not have the same visually Moreover, as patient safety is of utmost importance in in vivo examinations, the fact that the spectral emission of LEDs, unlike ?uorescent lights, does not contain a signi?cant amount of ultraviolet (UV) light is extremely bene?cial. This fact eliminates the need for the present invention to utilize UV ?lters, detectors and hardWare, all of Which are used in con impairing effect (i.e., glare) on the image as glint. When the ?rst total re?ected light reaches the PBS, that beam splitter both polarizes and splits the light into ?rst and second beams of light Which contain substantially perpen junction With UV emitting light sources to monitor, measure, control, or minimize UV output to prevent UV damage to the preferably directs the horizontally-polarized glint and any examined region. other diffuse re?ected light that has a horizontal orientation (a dicular polarization orientations to one another. The PBS The inventors are unaWare of any other imaging device that ?rst PP output) to a ?rst camera Which creates a ?rst PP incorporates the advantages of rapidly sWitching betWeen image. The secondbeam of light split by the PBS contains any different sets of LEDs to instantly, directly, and uniformly diffuse re?ected light With a polarization orientation that is substantially perpendicular to the ?rst beam (a ?rst XP out illuminate a ?eld of vieW for near-simultaneous imaging of put) and is directed to a second camera Which creates a ?rst tissue or an organ; and cross-polarization to suppress the negative effects of glint Without compromising the brightness of the image(s). 20 The ?rst presently preferred embodiment of the invention preferably uses tWo sets of LEDs. Each LED in a set has a separate non-moving (?xed or stationary) illumination polar izer (IP) in front of it, With the ?xed IP in front of each of the 25 Where the second polarization orientation is substantially per pendicular to the ?rst polarization orientation). This time, the second total re?ected light Will contain vertically-polarized 30 polarization orientation Which is substantially perpendicular output, and direct the second PP output (vertically-polarized glint and any diffuse re?ected light that has a vertical orien 35 appropriate polarization. a horizontal orientation) Will be directed by the PBS to the tional separate polarizing element, preferably a polarizing beam splitter (PBS), Which simultaneously polarizes and ined region. Ideally, a polarizing beamsplitter splits the beam into tWo beams that have orthogonal (perpendicular) polar izations so that the horizontally-polarized light (or light hav ing a ?rst polarization orientation) re?ects off the PBS and is directed toWard one camera, and vertically-polarized light (or light having a second polarization orientation) is transmitted through the PBS toWard the second camera. Thus, When the ?rst set of LEDs is turned on, the light ?rst camera to create a second XP image. 40 45 sWitching betWeen the tWo sets of LEDs (by rapidly sWitching one set on and the other set off, and vice versa), the tWo 50 (or light having a ?rst polarization orientation) Which directly illuminates a subject (such as tissue or an organ) in the ?eld of vieW. Part of the horizontally-polarized light re?ects off the 55 While the other part is partially absorbed by the subject and then re?ected as diffuse re?ected light (described beloW). The re?ected glint maintains its horizontal polarization (or ?rst polarization orientation) to become horizontally-polarized glint (or glint having a ?rst polarization orientation). The light that penetrates the tissue Will gradually become unpolarized 60 cameras in the device Will acquire four separate images of the same examined region, tWo images at a ?rst magni?cation, and tWo images at a second magni?cation. Of the tWo images at a ?rst magni?cation, one image Will be parallel-polarized and the other Will be cross-polarized. The same applies to the tWo images at a second magni?cation: one Will be parallel polarized and the other Will be cross-polarized. Rapidly sWitching betWeen the tWo sets of LEDs by elec tronically turning their operating current on and off, alloWs for near-simultaneous acquisition of images that are co-reg istered (co-aligned) by the tWo cameras and controls Whether the imaging system captures parallel- or cross-polarized images, and at What magni?cation the images are captured by after a su?icient number of scattering events, and a portion Will be re?ected from the tissue as diffuse re?ected light. The the cameras. PP images Will resemble standard colposcopic ?rst total re?ected light re?ected by the subject thus contains horizontally-polarized glint (or glint having a ?rst polariza The tWo cameras are preferably CCD (charged coupled device) or CMOS (complimentary metal oxide semiconduc tor) cameras that are co-aligned (aligned With each other) but have different magni?cations. The ?rst camera preferably has a ?rst magni?cation (a full-vieW or a magni?cation that alloWs the entire subject of interest to be imaged), and the second camera preferably has a second magni?cation (a mag ni?ed vieW or a magni?cation that alloWs for the vieWing of the smallest diagnostically important features). By rapidly passes through an IP to become horizontally-polarized light subject as horizontally-polarized glint (described beloW), tation) to the second camera Which creates a second PP image. The second XP output (any total re?ected light that has The present invention also preferably includes an addi splits an incident beam of light into tWo beams and directs the split beams toWards tWo cameras (detectors), so that each camera receives a differently polarized image of the exam glint (or glint having a second polarization orientation) and diffuse re?ected light. The PBS Will noW split the second total re?ected light into a second PP output and a second XP does not have be a vertical orientation but can be any second to the ?rst polarization orientation). Preferably, the lPs are integrally formed into a single polarizing element, With each LED in a set placed behind a corresponding region having the Alternatively, When the second set of LEDs is turned on, the light passes through an IP to become vertically-polarized light (or any light having a second polarization orientation, LEDs in the ?rst set having a horizontal orientation or being horizontally-polarized (it does not have to be a horizontal orientation but can be any ?rst polarization orientation), and the ?xed IP in front of each of the LEDs in the second set having a vertical orientation or being vertically-polarized (it XP image. For all preferred embodiments of the invention, the PP image Will alWays be created from the split beam of light Which contains glint, Whereas the XP image Will be created from the split beam of light that does not contain glint. 65 images, and although XP images Will be visually blurrier, they Will lack the glint present in the PP images. tion orientation) and diffuse re?ected light. While glint refers A second preferred embodiment comprises tWo sets of to light that is re?ected off one surface (e.g., the surface of the LEDs and uses one camera at a single level of magni?cation US 8,289,378 B2 11 12 or continuous magni?cation by the use of a zoom lens. In this information to the operator and technicians; and (iii) include comprehensive information, With respect to each image data second preferred embodiment, by rapidly switching betWeen set, about the state of the system When the images Were acquired. It also preferably contains a fully integrated user interface, in Which physical buttons are tied to the hardWare the tWo sets of LEDs, after passing the unpolarized light through an IP, the device Will acquire tWo near simultaneous images With the same magni?cation of the same examined region, one XP and one PP image. Although the use of a zoom and softWare platforms, permitting the functionality of the lens involves a mechanical movement of optical components With an associated time delay, it Would alloW for the acquisi management system With similar features is described in device to be adapted, if necessary, to neW functions. A data co-pending, commonly assigned US. patent application Ser. tion of XP and PP image pairs With different magni?cations. A third preferred embodiment is a simpler system Which is No. 1 1/184,046 entitled “Uterine Cervical Cancer Computer Aided Diagnosis”, ?led on Feb. 3, 2005, incorporated herein similar to the ?rst embodiment, but includes only one set of LEDs, and uses tWo cameras. In this preferred embodiment, by reference. light (or light having a ?rst polarization orientation) to The present invention is also preferably a self-contained system, meaning it is unnecessary to sWitch betWeen a col poscope and a physically separate computer to revieW and annotate images, and the system eliminates cable bundles that directly and uniformly illuminate a subject in a ?eld of vieW. Would otherWise be present betWeen a colposcope and a com The horizontally-polarized light that interacts With the sub ject is re?ected as total re?ected light that includes horizon tally-polarized glint and diffuse re?ected light. When the total re?ected light reaches the PBS, the PBS preferably directs the horizontally-polarized glint and any diffuse re?ected light puter. unpolarized light from the single set of LEDs is polarized When it passes through an IP to create horizontally-polarized The presently preferred embodiment of the invention also discloses a process of creating polarized light; illuminating a 20 having a horizontal orientation (PP output), to the ?rst camera Which creates the PP image, and directs any diffuse re?ected light into parallel-polarized and cross-polarized outputs; pro ducing a parallel-polarized image from the parallel polarized light having a vertical orientation @(P output) to the second camera Which creates the XP image. By adding zoom control to the cameras, PP and XP images at different magni?cations can be acquired. 25 BRIEF DESCRIPTION OF DRAWINGS 30 emphasizes the collection of glint-free @(P) images only. Again, the device polarizes unpolarized light from the single set of LEDs by passing the unpolarized light through an IP to create horizontally-polarized light (or light having a ?rst polarization orientation) to illuminate a subject in a ?eld of 35 vieW. The horizontally-polarized light that interacts With the subject is re?ected as total re?ected light that includes hori zontally-polarized glint and diffuse re?ected light. When the total re?ected light reaches the PBS, it directs any diffuse re?ected light having a vertical orientation (XP output) to the 40 45 50 region, in order to achieve optimal focus. Preferably, the tWo cameras are able to operate in video mode (loWer resolution but faster image capture) and camera mode (maximum reso lution at a loWer image capture rate for the acquisition high resolution imagery With all of the diagnostically features LEDs. FIG. 4A shoWs a con?guration containing a total of 8 LEDs, FIG. 4B shoWs a con?guration containing a total of 4 LEDs, and FIG. 4C shoWs a con?guration containing a total of 2 LEDS. FIGS. 5A and 5B are conceptual vieWs of the preferred embodiment to illustrate the process of cross-polarization. single camera system. FIG. 7A is a side conceptual vieW of the detection system The presently preferred embodiment of the invention also 60 for a tWo camera system, and FIG. 7B is a side conceptual vieW of the detection system for a one camera system. 65 FIGS. 8A, 8B, and 8C are schematics of the focusing subsystem Which shoW the camera object plane, the camera and the position of the focused light relative to the cervix, for three different focus states. In FIG. 8A, the cervix is in focus, in FIG. 8B, the cervix is too close, and in FIG. 8C, the cervix pletely digital data ?oW, simplifying data transfer and storage, and minimizing the risk of human error. The data manage ment system alloWs for (i) the use of image-enhancement algorithms; (ii) the use of image-processing algorithms; (iii) system diagnostics; (ii) present more comprehensive system tion) LEDs. FIG. 3A shoWs a con?guration containing a total of 8 LEDs; FIG. 3B shoWs a con?guration containing a total of 4 LEDs; and FIG. 3C shoWs a con?guration containing a total of 2 LEDS. FIGS. 4A, 4B, and 4C are conceptual front vieWs of the illumination system illustrating the con?guration for one set FIG. 6A is a front vieW of one of the camera systems, and FIG. 6B is a side vieW thereof. video mode to achieve satisfactory focus before the invention collects the XP and PP images in camera mode. the use of annotation programs; (iv) digital archiving; and (v) remote vieWing. This also alloWs the invention to (i) perform of horizontally-polarized (or having a ?rst polarization direc FIG. 5A shoWs a tWo camera system and FIG. 5B shoWs a 55 present). The focusing subsystem is preferably utilized in includes a data management system that alloWs for a com of LEDs. FIG. 2A shoWs a con?guration containing a total of 8 LEDs, FIG. 2B shoWs a con?guration containing a total of 4 LEDs, and FIG. 2C shoWs a con?guration containing a total of 2 LEDS. FIGS. 3A, 3B, and 3C are conceptual front vieWs of the of vertically-polarized (or second polarization direction) position of a focused beam of light (from eg a laser beam) to assess the distance betWeen the device and the examined FIG. 1 is a conceptual side vieW of the main components of the illumination system. FIGS. 2A, 2B and 2C are conceptual front vieWs of the illumination system illustrating the con?guration for tWo sets illumination system illustrating the con?guration for one set camera Which creates the XP image. By adding zoom control to the camera system, XP images at different magni?cations can be acquired. The presently preferred embodiment of the invention also includes a focusing subsystem (as described in co-pending, commonly assigned US. patent application Ser. No. 12/221, 267, entitled “Single Spot Focus Control” ?led Jul. 31, 2008, incorporated herein by reference) that utilizes the vertical output and a cross-polarized image from the cross-polarized output; and using the parallel polarized image and cross polarized image to enhance the visualization of tissue. A fourth preferred embodiment is simpler than all of the previously described embodiments. It uses only one set of LEDs and one camera. The fourth preferred embodiment ?eld of vieW With the polarized light; re?ecting the polarized light off a subject in the ?eld of vieW; splitting the re?ected is too far. FIG. 9 is a ?oW chart of the data management system. US 8,289,378 B2 13 14 BEST MODE FOR CARRYING OUT THE INVENTION tion. Again, a person of ordinary skill in the art could easily design the LED con?guration for a number of LEDs other than 2, 4, and 8 (for example, 6, l0, l2, 14, etc.). FIG. 5A and FIG. 5B illustrate the process of cross-polar ization in the preferred embodiment of the invention. The presence of light With a polarization orientation perpendicu lar to the plane of the paper (horizontally-polarized light) is indicated by an “O” (eg 70), and the presence of light With a polarization orientation parallel to the plane of the paper (vertically-polarized light) is indicated by an up and doWn Initially, a subject 72 (such as an organ or tissue) in a ?eld of vieW is directly illuminated by the presently preferred embodiment’s illumination subsystem, as shown in FIG. 1. The purpose of the illumination subsystem is to provide even and direct illumination of the subject in the ?eld of vieW With suf?cient intensity (brightness) for the invention to acquire images quickly enough to avoid or minimize blur due to motion (for eg patient movement). The illumination sub system preferably comprises the folloWing main compo nents: (a) front lens 34, (b) illumination polarizer (IP) 36, (c) doWn arroW denotes unpolarized light (eg 66). LED lenses 42, (d) one or more sets of LEDs 49, (e) illumi by illuminating a ?eld of vieW With unpolarized light 66 from arroW (eg 82). The presence of both an “O” and an up and As illustrated in FIG. 5A, XP and PP images are obtained nation board 50 With control electronics and (f) poWer supply 15. The laser 51 of the focusing system is also shoWn, as is the at least one set of LEDs 49, Which is ?ltered through an IP 36 to produce horizontally-polarized light (or any light having a ?rst polarization orientation) 70. When the horizontally-po subject 72 being illuminated, and the light beam direction 70 of the illumination system. The LEDs 49 are preferably mounted onto the illumination board 50, Which also provides control electronics to set the operating current and voltage, and to rapidly turn the LEDs 49 on and off. The LED lenses 42 focus the divergent light from the unpolarized LED 49 into light output beams 66. An IP 36 is placed in front of the LED lenses 42. The front lens 34 directs the polarized LED light output 70 toWards the subject 72 to illuminate the entire ?eld of vieW that contains the subject 72. Front vieWs of the illumination system shoWing the LEDs 49, IP 36, and front lens 34 are displayed in FIG. 2A-2C, FIG. 3A-3C, and FIG. 4A-4C. Con?gurations for tWo sets of LEDs are illustrated in FIG. 2A-2C Whereas con?gurations for one set of LEDs are illustrated in FIG. 3A-3C and FIG. 4A-4C. larized light 70 interacts With a subject 72 (such as cervical 20 tissue) in the ?eld of vieW, it partially penetrates the tissue, and is also partially re?ected as horizontally-polarized glint (or glint having a ?rst polarization orientation). A portion of the light that penetrates the tissue Will gradually become unpolarized, and re?ect from the tissue as diffuse re?ected light. The total re?ected light 74 Will be a combination of both 25 (i) the horizontally-polarized glint, and (ii) the diffuse re?ected light. When the total re?ected light 74 reaches an additional polarizing element designed to split the light into perpendicular orientations (such as a polarizing beam splitter or PBS 22), it splits the total re?ected light into a PP output 76 30 and a XP output 82 that are received by separate cameras 20 and 24. The PP output creates the PP image, and contains The polarizing direction of the light is indicated by the horizontally-polarized glint and any diffuse re?ected light arroWs. having the same polarization (horizontally-polarized diffuse re?ected light). The PP image Will look substantially similar to standard colposcopic data. The other output, the XP output, FIGS. 2A-2C illustrate the preferred embodiment using tWo sets of LEDs 49, the solid arroWs designating the ?rst set of LEDs 49 and the outlined arroWs designating the second set of LEDs 49. The direction of the arroWs designates the 35 is vertically-polarized (vertically-polarized does not mean the light has to be vertically-polarized but can be any light polarization orientation of the LED light 70 after being trans having a second polarization orientation that is at a substantial mitted by the IP 36. The outlined arroWs have a horizontal polarization orientation (or a ?rst polarization orientation), 40 angle to the ?rst polarization described above, preferably substantially perpendicular), and contains only the diffuse and the solid black arroWs have a vertical orientation (or a re?ected light having the same vertical-polarization, but no second polarization orientation). For tWo sets of LEDs 49, the IP 36 is preferably designed to polarize the light from each set of LEDs 49 such that the second polarization orientation is glint. Thus, a ?rst camera 20 creates a PP image and a second camera 24 creates the XP image. FIG. 5B illustrates the concept of using one camera 24 only substantially perpendicular to the ?rst polarization orienta 45 of one of the cameras and FIG. 6B is a side vieW thereof. As 49 With perpendicular polarization orientations (i.e. tWo polarization orientations), the con?guration Will preferably 50 be designed With the total number of LEDs as a multiple of 2 to ensure similar intensity (brightness) and uniform illumi nation for both polarization orientations. Although not shoWn 55 such as 6, l0, l2, 14, etc. The circular design and alternating illumination for both polarization orientations. possible image resolution is preferably achieved, at the 60 tion of the arroWs again designating the polarization orienta tion of the light from the LED. Here, the IP 36 is designed to polarize the light from the LEDs 49 in a single polarization orientation only. FIG. 3A, FIG. 3B and FIG. 3C, and FIG. 4 A, FIG. 4B and FIG. 4C illustrate the use of 8, 4, and 2 LEDs, respectively. Here any number of LEDs can be used; hoWever, a circular con?guration Will again ensure uniform illumina a regular video camera for positioning and manual focus. In this mode, a loW resolution, high frame rate image stream is produced. In camera mode, the present invention Will tempo rarily change the imaging sensor settings so that the highest polarization orientation of the LEDs 49 Will ensure uniform FIGS. 3A-3C and FIGS. 4A-4C, illustrate an alternative embodiment Which uses only one set of LEDs 49, the direc seen in FIGS. 6A and 6B, each camera preferably comprises the folloWing components: an imaging sensor 83, a lens mount 84, an output cable connector housing 85, and an output cable connector 86. The sensor 83 is preferably able to run in tWo modes of operation: video mode and camera mode. In video mode, the operator manipulates the device much like in FIG. 2A-2C, a person of ordinary skill in the art could easily design the LED con?guration for additional LEDs, and, thus, acquiring an XP image only. FIG. 6A and FIG. 6B illustrate the camera con?guration of the presently preferred embodiment. FIG. 6A is a front vieW tion. FIG. 2A, FIG. 2B, and FIG. 2C illustrate the use of 8, 4, and 2 LEDs, respectively, to achieve illumination With light of perpendicular polarization orientations. For tWo sets of LEDs expense of a loWer frame rate. The ?nal XP and PP images of the present invention are preferably acquired in camera mode, and are stored for later revieW, image annotation, and pro cessing. XP and/ or PP images can also be registered (aligned) 65 and then faded into each other to aid a clinician in arriving at a diagnosis FIG. 7A shoWs a side vieW of a presently preferred embodi ment of the detection system Which contains tWo cameras, US 8,289,378 B2 15 and FIG. 7B shows a side vieW of another embodiment of the detection system Which contains only one camera. The place ment of the front lens 34, polarizing element (such as a polarizing beam splitter) 22, and the cameras 20 and 24 are shoWn therein. For a tWo camera system, as seen in FIG. 7A, the optics of the ?rst camera 20 are preferably designed to capture a full 16 The presently preferred embodiment of the invention also includes a data management system. FIG. 9 shoWs a ?owchart 5 of the data management system. The data management sys tem 3, includes a database of image and patient data, and interacts With the data acquisition system 7 and external sources, such as PACS (Picture Archiving and Communica tion System) 10, pathology reports 11, patient data records ?eld of vieW of the subject, and the secondary optics of the 12, telemedicine applications 13, and optional other sources second camera 24 are preferably designed to capture a mag de?ned by the user 14. PACS refer to computers or netWorks ni?ed vieW of a smaller region-of-interest (typically being able to resolve the smallest diagnostically relevant feature). In dedicated to the storage, retrieval, distribution and presenta tion of images. The medical images are preferably stored in a format that is independent of this invention and Widely used. The most common format for medical image storage is pres the preferred embodiment Which uses tWo sets of LEDs, the optical paths of the tWo sets of LEDs are polarized perpen dicular to one another after being split by the PBS 22, and ently DICOM (Digital Imaging and Communications in depending on Which set of LEDs is turned on, the image outputs received and displayed by both cameras Will be either Medicine). (i) a full-vieW XP image; (ii) a magni?ed region-of-interest vieW PP image; (iii) a full-vieW PP image; or (iv) a magni?ed region-of-interest XP image. The PP and XP images are sub digital data ?oW, simplifying data transfer and storage, and stantially co-registered because of the rapid sWitching This data management system alloWs for a completely minimizing the risk of human error. The data management 20 betWeen (or sWitching on and off) of the illumination source (LEDs), and can be used in conjunction With each other for system alloWs for (i) the use of image-enhancement algo rithms; (ii) the use of image-processing algorithms; (iii) the use of annotation programs; (iv) digital archiving; and (v) remote vieWing. This also alloWs the invention to (i) perform diagnostic purposes, for example, fading betWeen them. In system diagnostics; (ii) present more comprehensive system the embodiment Which uses only one set of LEDs, the optics of the tWo camera systems 20 and 24 are preferably designed to capture the same ?eld of vieW of the subject, this vieW being either the full-vieW or a magni?ed region-of-interest information to the operator and technicians; and (iii) include comprehensive information, With respect to each image data 25 set, about the state of the system When the images Were acquired. It also preferably contains a fully integrated user interface, in Which physical buttons are tied to the hardWare vieW. Here, the image outputs received and displayed Will be and softWare platforms, permitting the functionality of the either (i) a full-vieW (or magni?ed) XP image or (ii) a full vieW (or magni?ed) PP image. 30 device to adapt, if necessary, to neW functions. For a single (one) camera system, as seen in FIG. 7B, the optics of the camera 24 are preferably either a ?xed focal INDUSTRIAL APPLICABILITY length lens con?gured to capture the full ?eld of vieW of the subject, or a zoom lens con?gured to capture the full ?eld of vieW of the subject as Well as a magni?ed vieW of the subject. This invention uses LEDs and cross-polarization to pro 35 The presently preferred embodiment of the invention also includes a focusing subsystem Which helps achieve optimal focus of the images. This focusing subsystem analyzes images taken in the video mode to assess if the invention is in focus before images are acquired in camera mode. As dis played in FIGS. 8A, 8B and 8C, a focus light source (eg a focused LED or a laser) 51 produces a focus beam 53 that is focused toWard the optical axis 60 through a lens 34, the displacement of the focus beam (Ay) in the ?eld of vieW of the camera uniquely determines the distance (Az) needed to align the examined region (region or object of interest) 72 With the camera object plane 62, Where the focus beam 53 meets the optical axis 60. When the examined region is aligned With the camera object plane, as seen in FIG. 8A, the examined region is ‘in focus’ . When the focus beam is in the loWer pixels of the images) and parallel-polarized images (images With glint), preferably at multiple magni?cations. The invention is appli 40 of vieW by using at least one image With glint and a glint-free image. 45 degrees. Preferably the angle 0t should be approximately in the range of 4 to 15 degrees. Optimally, the angle should be approximately in the range of 5 to 8 degrees. What is claimed is: 1 . A device for enhancing visualization of tissue in a ?eld of vieW comprising: 50 a ?rst set of LEDs to emit light onto said ?eld of vieW, Whereby When said ?rst set of LEDs is turned on, said ?rst set of LEDs emits light onto said ?eld of vieW through a ?rst illumination polarizer placed betWeen said ?rst set of LEDs and said ?eld of vieW, to create 55 polarized light in said ?eld of vieW having a ?rst polar ization orientation, and Wherein said polarized light hav ing said ?rst polarization orientation is re?ected by said tissue as ?rst total re?ected light; a second set of LEDs to emit light onto said ?eld of vieW, Whereby When said second set of LEDs is turned on, said second set of LEDs emits light onto said ?eld of vieW direction the operator should move the device to achieve optimal focus. Although the focus light source 51 is shoWn to be located beloW the optical axis 60 in FIG. 8A, FIG. 8B and FIG. 8C, it can be positioned anyWhere off the optical axis. The system is operable as long as the focus beam and the optical axis are Within a certain angle (B) of each other, and the focus beam is not obstructed by any object other than the region of interest. The focus system is operable When the angle 0t is approximately betWeen the ranges of 2 to 60 cable to any imaging device in Which it is desirable to enhance visualization of a subject (such as tissue or an organ) in a ?eld image, the examined region is too close, as shoWn in FIG. 8B, and the subsystem is ‘out of focus’. When the focus beam is in the upper pixels of the image, the examined region is too far, as seen in FIG. 8C, and the subsystem is also ‘out of focus’. The output of the focusing subsystem suggests Which duce bright, high-resolution digital images, both With and Without glint, that preserves image clarity While suppressing glint, and creates both cross-polarized images (glint-free 60 through a second illumination polarizer placed betWeen said second set of LEDs and said ?eld of vieW, to create polarized light in said ?eld of vieW having a second polarization orientation, and Wherein said polarized light having said second polarization orientation is 65 re?ected by said tissue as second total re?ected light; Wherein said ?rst set of LEDs and said second set of LEDs all emit visible light of the same color; US 8,289,378 B2 17 wherein said second polarization orientation is substan tially perpendicular to said ?rst polarization orientation; a polarizing element to receive said ?rst total re?ected light and said second total re?ected light and split said total re?ected light into a ?rst parallel-polarized output and a ?rst cross-polarized output When said ?rst set of LEDs is illuminated, and a second parallel-polarized output and a second cross-polarized output When said second set of LEDs is illuminated; a ?rst camera to receive said ?rst parallel-polarized output 10 to create a ?rst parallel-polarized image When said ?rst 18 3 . A device for enhancing visualization of tissue in a ?eld of vieW comprising: a ?rst set of LEDs to emit light onto said ?eld of vieW, Wherein all LEDs in said ?rst set of LEDs emit visible light of the same color; an illumination polarizer placed betWeen said ?rst set of LEDs and said ?eld of vieW to cause said light emitted onto said ?eld of vieW; to become horizontally-polar ized light, Wherein said horizontally-polarized light is re?ected by said tissue as total re?ected light; a polarizing element to receive said total re?ected light that set of LEDs is illuminated, and to receive said second cross-polarized output to create a second cross-polarized image When said second set of LEDs is illuminated; both polarizes and splits said total re?ected light into ?rst and second beams of light Which contain substan tially perpendicular polarization orientations to one a second camera to receive said ?rst cross-polarized output 15 another, Wherein one of said polarization orientations is to create a ?rst cross-polarized image When said ?rst set of LEDs is illuminated, and to receive said second parallel-polarized output to create a second parallel-polarized image When said second set of LEDs is illuminated; electronic sWitching means to rapidly sWitch betWeen illu- 20 minating said ?rst set of LEDs and illuminating said second set of LEDs to reduce in?uence from patient movement betWeen successive images, alloWing forbetter registration betWeen said successive images; and Whereby said parallel-polarized images and said cross- 25 substantially parallel to polarization of said horizon tally-polarized light and the other of said polarization orientations is substantially perpendicular to polariza tion of said horizontally-polarized light, Whereby said polarizing element receives said total re?ected light and splits said total re?ected light into a parallel-polarized output and a cross-polarized output; a ?rst camera to receive said cross-polarized output to polarized images enhance visualization of said tissue. create a cross-polarized image; asecond camera to receive saidparallel-polarizedoutputto create a parallel-polarized image; and 2. A device for enhancing visualization of tissue in a ?eld of Whereby said cross-polarized image and said parallel-po vieW comprising: larized image enhance visualization of said tissue. 4. A device according to any one of claim 1 or 2, Wherein a ?rst set of LEDs to emit light onto said ?eld of vieW, Whereby When said ?rst set of LEDs is turned on, said 30 said ?rst illumination polarizer and said second illumination ?rst set of LEDs emits light onto said ?eld of vieW polarizer are preferably integrally formed. through a ?rst illumination polarizer placed betWeen 5. A device according to any one of claim 1 or 3, Wherein said ?rst camera is at a ?rst magni?cation and said second said ?rst set of LEDs and said ?eld of vieW, to create camera is at a second magni?cation, Wherein said second polarized light in said ?eld of vieW having a ?rst polar ization orientation, and Wherein said polarized light hav- 35 magni?cation is greater than said ?rst magni?cation. ing said ?rst polarization orientation is re?ected by said 6. A device according to any one of claim 1, 2, or 3, further tissue as ?rst total re?ected light; comprising a focusing subsystem to achieve optimal focus. a second set of LEDs to emit light onto said ?eld of vieW, 7. A device according to any one of claim 1, 2, or 3, further Whereby When said second set of LEDs is turned on, said comprising a computerized data management system for second set of LEDs emits light onto said ?eld of vieW 40 archival purposes and for the annotation of digital data. through a second illumination polarizer placed betWeen said second set of LEDs and said ?eld of vieW, to create 8. A process to suppress glint and preserve image clarity comprising: polarization orientation, and Wherein said polarized polarizing unpolarized light from LEDs to produce polar ized light having a ?rst polarization orientation; light having said second polarization orientation is 45 re?ected by said tissue as second total re?ected light; Wherein said second polarization orientation is substan- illuminating a ?eld of vieW containing tissue With said polarized light having a ?rst polarization orientation; re?ecting said polarized light off said tissue as total polarized light in said ?eld of vieW having a second tially perpendicular to said ?rst polarization orientation; re?ected light; apolarizing element to receive said ?rst total re?ected light and said second total re?ected light and split said total 50 re?ected light into a ?rst parallel-polarized output and a ?rst cross-polarized output When said ?rst set of LEDs is illuminated, and a second parallel-polarized output and a second cross-polarized output When said second set of LEDs is illuminated; 55 a camera to receive one of said cross-polarized outputs to create a cross-polarized image When one of said set of polarizing and splitting said total re?ected light into a parallel-polarized output and a cross-polarized output; rapidly electronically sWitching betWeen said parallel-po larized output and said cross-polarized output to reduce in?uence from patient movement betWeen successive images, alloWing for better registration betWeen succes sive images; collecting said rapidly electronically sWitched parallel-po larized outputs and said cross-polarized outputs; LEDs is illuminated, and to receive one of said parallel- producing a set of cross-polarized images from said cross polarized outputs to create a parallel-polarized image When the other set of LEDs is illuminated; 60 electronic sWitching means to rapidly sWitch betWeen illu minating said ?rst set of LEDs and illuminating said polarized output and a set of parallel-polarized images from said parallel polarized outputs; and Whereby said set of cross-polarized image and said set of parallel-polarized images can be registered and faded second set of LEDs to reduce in?uence from patient into each other to enhance visualization of said tissue. movement betWeen successive images, alloWing for bet 9. A process to suppress glint and preserve image clarity ter registration betWeen said successive images; and 65 comprising: Whereby said cross-polarized image and said parallel-po larized image enhance visualization of said tissue. polarizing unpolarized light from LEDs to produce polar ized light having a ?rst polarization orientation; US 8,289,378 B2 19 illuminating a ?eld of vieW containing tissue With said polarized light having a ?rst polarization orientation; re?ecting said polarized light off said tissue as total re?ected light; polarizing and splitting said total re?ected light into a parallel-polarized output and a cross-polarized output; rapidly electronically sWitching betWeen said parallel-po larized output and said cross-polarized output to reduce in?uence from patient movement betWeen successive images, alloWing for better registration betWeen succes sive images; 20 collecting said rapidly electronically sWitched cross-polar ized outputs; producing a set of cross-polarized images from said cross polarized outputs; and Whereby said set of cross-polarized images enhances visu alization of said tissue by removing glint to alloW for deeper layers of said tissue to be visualized at multiple magni?cations.